Recently, raw garbage discharged from household and business in urban area, feces and urine in the livestock field including cow dung and poultry manure, organic waste derived from swage treatment, organic industrial waste, and the like have remarkably increased, and hence the facilities for treating them are at the absolute edge of exceeding their capacity.
In such a situation, it has been proposed to convert those wastes into compost through decomposition/digestion treatment or composting thereof by the action of microorganisms. However, the microorganisms involved in decomposition/digestion thereof are usually derived from self-generation, and hence it requires a long period of time to achieve a certain concentration of the microorganisms necessary for the treatment.
On the other hand, in a continuously-working system such as a raw garbage-treating machine, according to the frequently-repeated rise and fall of material temperature, bacterial flora is not stabilized, and it becomes one of the factors of affording no stable effect. As a means for accelerating microorganism generation and promoting efficient treatment, treating agents containing various microorganisms and the like have been also disclosed.
For example, with focusing on the process in which the material temperature of organic waste is elevated from the room temperature to a high temperature of about 50 to 70° C., a treating agent in which spores of the genus Bacillus are mixed has been disclosed as a treating agent for composting organic waste, for the purpose of maintaining the temperature in the process (for example, cf. Patent Document 1).
However, in a high temperature range, since these microorganisms stop their action to form cysts, a large rise and fall of the material temperature during the treatment is observed, and hence bacterial flora is destabilized. Accordingly, it invites a lowered pH of the object to be treated and a proliferation of unwanted bacteria to cause a decrease in treating efficiency, malodor, and the like. Thus, there arises a problem that the stable treating effect cannot be obtained. Furthermore, since moisture is not evaporated at a high temperature, it is necessary to control an initial water content, and hence there is a problem in view of labor and cost.
Additionally, there has been disclosed a method in which a rapid temperature elevation and a high protease activity at 50° C. or higher are achieved using a microorganism belonging to bacteria of Bacillus to improve the decomposition-treating capacity of organic waste (for example, cf. Patent Document 2).
However, it is necessary to culture the bacteria for use in the treatment for 3 days beforehand, and hence the method is far from the substantial improvement. Furthermore, since it is necessary to use the bacteria in the same amount as that of the object to be treated in the actual treatment, there is a problem in view of a treating capacity and cost.
Patent Document 1: JP-A-9-12387 (pages 1 to 2)
Patent Document 2: JP-A-7-303478 (pages 1 to 2)
An object of the present invention is to overcome the defects of the above conventional technologies, and the present invention provides a method of treating organic waste, which is excellent in smooth temperature elevation in the early stage of the treatment and is satisfactory in temperature-maintenance in a high temperature range, and by which a stable treatment of organic waste can be achieved and the evaporation of moisture is promoted, thereby a stable effect of treating organic waste and an increase in treatment scale being achieved; an agent for treating organic waste; and microorganisms to be used therein.